The latest data from CERN hints at a whole new force of nature


When CERN’s gargantuan accelerator, the Large Hadron Collider (LHC), went off ten years ago, hopes abounded that new particles would soon be discovered that could help us unravel the deepest mysteries of the Earth. physical. Dark matter, microscopic black holes and hidden dimensions were just a few of the possibilities. But other than the spectacular discovery of the Higgs boson, the project gave no clue as to what might lie beyond the Standard Model of particle physics, our current best theory of the micro-cosmos.

So our new document from LHCb, one of the four giant experiments at the LHC, is likely to make physicists’ hearts beat a little faster. After analyzing the billions of collisions produced over the past decade, we can see evidence of something entirely new – potentially the bearer of a whole new force of nature.

But the excitement is tempered by extreme caution. The Standard Model has withstood all the experimental tests launched since it was assembled in the 1970s, so claiming we’re finally seeing something it can’t explain requires extraordinary evidence.

Strange anomaly

The Standard Model describes nature on the smallest scale, comprising fundamental particles called leptons (such as electrons) and quarks (which can come together to form heavier particles such as protons and neutrons) and the forces with which they interact with.

There are many types of quarks, some of which are unstable and can decay into other particles. The new result is linked to an experimental anomaly that was first mentioned in 2014, when physicists at the LHCb spotted “beauty” quarks disintegrating unexpectedly.

Specifically, beauty quarks seemed to decay into leptons called “muons” less often than they decay into electrons. This is strange because the muon is essentially a carbon copy of the electron, identical in every way except that it is about 200 times heavier.

One would expect beauty quarks to decay to muons as often as they do to electrons. The only way these decays could occur at different rates is if particles never seen before were involved in the decay and tip the balance against muons.

While the 2014 result was intriguing, it wasn’t specific enough to draw a firm conclusion. Since then, a number of other anomalies have appeared in related processes. They were all individually too subtle for researchers to be convinced these were true signs of a new physics, but enticingly, they all seemed to point in a similar direction.

Image of the LHCb experiment.